Anderson, Bradley W.

Abstract Purpose: Gastric adenocarcinoma is the third most common cause of cancer mortality worldwide. Accurate and affordable noninvasive detection methods have potential value for screening and surveillance. Herein, we identify novel methylated DNA markers (MDM) for gastric adenocarcinoma, validate their discrimination for gastric adenocarcinoma in tissues from geographically separate cohorts, explore marker acquisition through the oncogenic cascade, and describe distributions of candidate MDMs in plasma from gastric adenocarcinoma cases and normal controls. Experimental Design: Following discovery by unbiased whole-methylome sequencing, candidate MDMs were validated by blinded methylation-specific PCR in archival case–control tissues from U.S. and South Korean patients. Top MDMs were then assayed by an analytically sensitive method (quantitative real-time allele-specific target and signal amplification) in a blinded pilot study on archival plasma from gastric adenocarcinoma cases and normal controls. Results: Whole-methylome discovery yielded novel and highly discriminant candidate MDMs. In tissue, a panel of candidate MDMs detected gastric adenocarcinoma in 92% to 100% of U.S. and South Korean cohorts at 100% specificity. Levels of most MDMs increased progressively from normal mucosa through metaplasia, adenoma, and gastric adenocarcinoma with variation in points of greatest marker acquisition. In plasma, a 3-marker panel (ELMO1, ZNF569, C13orf18) detected 86% (95% CI, 71–95) of gastric adenocarcinomas at 95% specificity. Conclusions: Novel MDMs appear to accurately discriminate gastric adenocarcinoma from normal controls in both tissue and plasma. The point of aberrant methylation during oncogenesis varies by MDM, which may have relevance to marker selection in clinical applications. Further exploration of these MDMs for gastric adenocarcinoma screening and surveillance is warranted. Clin Cancer Res; 24(22); 5724–34. ©2018 AACR.

97 Background: A diagnosis of EC significantly impairs patient (pt)’s survival and quality of life (QoL). We explored the relationship between pt-assessed QoL and survival. Methods: The Mayo Clinic Romero (formerly Esophageal Adenocarcinoma-Barrett's Esophagus) Registry prospectively collects clinical data during a pt's treatment course. QoL is recorded at enrollment (baseline) and annually using a validated 12-item Linear Analog Self-Assessment (LASA). A 10-pt scale is applied; ≤5 was termed clinically deficient QoL. Initial TNM staging, clinical (age, sex, prior chemotherapy, and esophagectomy), and socioeconomic variables (marital/employment status) were analyzed using Cox proportional hazards regression models. Results: 836 pts were analyzed. Median age was 64 years. 166, 506 and 164 pts had early, locally advanced, and metastatic EC, with 5-year survival rates of 75.1%, 33.6%, and 8.1%, respectively (P≤.0001). Poorer survival rates were seen in clinically QoL deficient pts in the following categories: Overall QoL (Hazard Ratio [H.R.] 0.66; 95% C.I., 0.54-0.80; P≤.0001) and LASA subsets for physical (H.R. 0.68; 95% C.I., 0.57-0.82; P≤.0001), emotional well-being (H.R. 0.69; C.I., 0.57-0.84; P=.0003), and social activity (H.R. 0.76; C.I., 0.63-0.91; P=.0028). No difference in survival was observed for marital or employment status, familial support, and financial/legal concerns. Pts with esophagectomy prior to LASA evaluation had improved survival (H.R. 0.68; 95% C.I., 0.55-0.85; P=.0005). No survival difference was observed whether pts received chemotherapy, before or after their baseline LASA evaluation. Conclusions: A strong association exists between pt’s overall survival and better overall QOL, physical, emotional well-being, and social activities. Using LASA to clinically monitor QoL at specified intervals may afford providers the opportunity to intervene when patients begin to experience QoL decline. The determinants of clinically deficit QoL and its impact on survival warrant further translational and prospective research.